Memory allocation of vector of numbers


examples/vectors/memory-integers/src/main.rs
macro_rules! prt {
    ($var: expr) => {
        println!(
            "{:2} {:2} {:p} {:?} {:?}",
            $var.len(),
            $var.capacity(),
            &$var,
            $var.as_ptr(),
            $var
        );
    };
}

macro_rules! prtn {
    ($var: expr) => {
        println!(
            "{:2} {:2} {:p} {:?} {:?}",
            $var.len(),
            $var.capacity(),
            &$var,
            $var.as_ptr(),
            $var
        );
        for ix in 0..$var.len() {
            println!("{:2}    {:p} {:?}", ix, &$var[ix], $var[ix]);
        }
    };
}
fn main() {
    let mut numbers: Vec<i32> = vec![19, 23];

    prtn!(numbers);
    println!();
    let x = String::from("hi");
    prt!(x);

    numbers.extend([1, 2, 3, 4]);
    prtn!(numbers);
    println!();

    numbers.extend([5]);
    prtn!(numbers);
    println!();
}





 2  2 0x7ffcee29d998 0x5fc29ca5db80 [19, 23]
 0    0x5fc29ca5db80 19
 1    0x5fc29ca5db84 23

 2  2 0x7ffcee29e060 0x5fc29ca5dba0 "hi"
 6  6 0x7ffcee29d998 0x5fc29ca5db80 [19, 23, 1, 2, 3, 4]
 0    0x5fc29ca5db80 19
 1    0x5fc29ca5db84 23
 2    0x5fc29ca5db88 1
 3    0x5fc29ca5db8c 2
 4    0x5fc29ca5db90 3
 5    0x5fc29ca5db94 4

 7 12 0x7ffcee29d998 0x5fc29ca5dbc0 [19, 23, 1, 2, 3, 4, 5]
 0    0x5fc29ca5dbc0 19
 1    0x5fc29ca5dbc4 23
 2    0x5fc29ca5dbc8 1
 3    0x5fc29ca5dbcc 2
 4    0x5fc29ca5dbd0 3
 5    0x5fc29ca5dbd4 4
 6    0x5fc29ca5dbd8 5